"Paramilitary trappings should not blind people to the fact that what is at issue is criminal terrorism carried on by people who, for their own reasons, want to drag the people of this island back to a dark past," Shatter said.

"In treating the will of the people, north and south, with contempt, they dishonour democracy.”

"I recognise fully the immediate difficulties which face An Garda Siochana when people take advantage of a funeral to behave in this fashion. But the Garda Commissioner has assured me that they are pursuing rigorously any breaches of the law which took place.”

The Belfast Telegraph reports that during Ryan’s funeral on Saturday, members of the Real IRA fired off rounds of gunshots as his body was taken from his North Dublin home for the funeral. The paramilitary group was out in strength, following the funeral procession from Ryan’s home to the Church and then onto the graveyard.

Ryan’s coffin was draped with a tricolor and escorted by hundreds of supporters and associates dressed in republican uniform, including a colour party with their faces covered. The funeral was held at the Church of the Holy Trinity in Donaghmede, North Dublin, and was monitored by a strong Garda presence.

Alan Ryan was gunned down last Monday near his home in the Grange Lodge estate in Clongriffin, Dublin. A suspect who is in his 40s was arrested on Thursday and can be questioned for up to 72 hours.

Ryan was no stranger to crime, and had served time in 2000 after the discovery of a Real IRA training camp. He was being investigated for crimes in both the North and Republic of Ireland.

"The gardai, together with their colleagues in the north, will continue to take every action open to them to deal with the activities of members of these groups, whether they are engaging in terrorism or organised crime."

While Sinn Fein councillor Micheal Mac Donncha admitted the murder of Ryan was shocking, he warned that dissidents do not have the support of the local community. "As a public representative, I have to reflect the views of the local community, and it has to be said that there is great resentment at attempts to portray the so-called 'Real IRA' as being supported by this community," said Mr Mac Donncha.

"Wall slogans and black flags cannot hide the fact that this violent faction is rejected by the community in Donaghmede and that they represent no-one but themselves. Genuine Irish republicans throughout the country totally reject the activities of this group and other such factions who abuse the good name of Irish republicanism to further their own ends."